1. Field of the Invention
The present invention relates to a driving linkage device applicable to a variable nozzle mechanism in a supercharger turbine or a variable diffuser mechanism in a compressor.
2. Description of the Prior Art
As a variable nozzle mechanism of a supercharger turbine, for instance, those having the structure shown in FIG. 2 have been heretofore known. In this figure, reference numeral 1 designates a driving ring rotated by an actuator 2. Along the inner circumferential surface of this driving ring 1 are disposed a bearing 3 divided into a plurality of bearing pieces, and at the center of the above-mentioned driving ring 1 is disposed a radial turbine 4. To the above-described driving ring 1 are mounted a plurality of nozzle vanes 5. Each of these nozzle vanes 5 is composed of a vane main body 6 and a lever 7. At one end of this lever 7 is formed a U-shaped slot, and this slot is engaged with a pin 8 studded on the above-mentioned driving ring 1. Also, the other end of the above-described lever 7 is connected to the afore-mentioned vane main body 6 via a fulcrum 9, and the above-mentioned vane main body 6 can freely rotate about that fulcrum 9.
In the variable nozzle mechanism having the above-described construction, if the driving ring 1 is rotated by the actuator 2, the plurality of pins 8 studded on that ring 1 are also moved, hence according to this movement, the levers 7 of the respective nozzle vanes 5 engaged with the respective pins 8 via the slots are driven, and the vane main bodies 6 rotate about the respective fulcrums 9. Accordingly, in response to the movement of the vane main bodies 6 of the respective nozzle vanes 5 coupled to the driving ring 1, a stroke-width W between the nozzle vanes 5 changes, and thereby an adjusting operation for the variable nozzle is carried out.
However, in the above-described construction, since the drive in the circumferential direction of the driving ring 1 is effected by applying a force to one location on the driving ring 1 to which the actuator 2 is coupled, a large force is exerted upon the driving ring 1 in one direction. As a result, the contact between the driving ring 1 and the bearing 3 takes the state like point contact, and so, where was a problem in that anomalous abrasion would arise between the driving ring 1 and the bearing 3.